Typical studies of concept learning in adults address the learning of novel concepts, but much of learning involves the updating and restructuring of familiar concepts. Research on conceptual change explores this issue directly but differs greatly from the formal approach of the adult learning studies. This paper bridges these two areas to advance our knowledge of the mechanisms underlying concept restructuring. The main idea behind this approach is that concepts are built on causal-explanatory knowledge, and hence, models of causal induction may help to clarify the mechanisms of the restructuring process. A new paradigm is presented to study the learning and revising of causal networks. Experiments 1 and 2 showed that learners’ prior beliefs about the causal relations in a domain affected their hypotheses as they began to infer the correct causes. First, when the prior learning suggested evidence against some of the incorrect causes, this helped learners to focus on the correct causes later in learning. Second, the prior causal beliefs were difficult to give up, and they biased learners away from the correct causes that competed to explain the same effects. Experiment 3 showed that learning by intervention, as opposed to observation, affected the concept restructuring process in different ways, depending on what interventions were chosen and by whom. People choosing their own interventions revealed a confirmation bias to preserve their prior beliefs, but those with no choice used the same interventions to disconfirm their prior beliefs. Taken together, these studies represent the beginnings of a larger research effort to use the analytic tools from causal induction to reveal the mechanisms behind larger shifts in knowledge, as evidenced by developing children and experts.